This invention relates to a method and apparatus for removing ethylene oxide from gas compositions containing ethylene oxide and more particularly to a method and apparatus for removing ethylene oxide from a gaseous effluent utilized to sterilize articles, particularly for medical use.
At the present time, it is common practice to sterilize articles, particularly articles for medical use, with ethylene oxide. Typically, the article to be sterilized is placed in a chamber which is evacuated. The ethylene oxide is introduced into the evacuated chamber and allowed to remain therein until the article is sterilized, usually from about 1 to 3 hours. The ethylene oxide then is vented from the chamber into the surrounding atmosphere. Presently, the ethylene oxide is available from cartridges in three standard sizes of about 30 g, 70 g and 134 g which corresponds to their use in 1 ft.sup.3, 2 ft.sup.3 and 4 ft.sup.3 gas sterilization instruments respectively. In these sizes, the cartridges can be hand-carried easily to a desired location which is desirable, if not essential in most medical environments such as hospitals.
Unfortunately, ethylene oxide is a toxic material and special precautions must be taken to assure that it is vented to an area remote from persons. Generally, venting systems are provided so that the ethylene oxide is directed outside of the building within which persons are present. However, even these systems are hazardous since there is still the possibility that persons outside of the building unknowingly could come into contact with the ethylene oxide before it has been sufficiently diluted in the outside atmosphere. Also, it is not uncommon for the exhausted ethylene oxide to be vented into a wet sponge located in a container within a working area.
Accordingly, it would be highly desirable to provide a means for neutralizing the toxic effects of ethylene oxide. In addition, it would be desirable to provide such a means which can be rendered portable to afford quick and efficient use, particularly in a medical environment. Also, it would be desirable to provide such a process wherein dissolved ethylene oxide is not entrained from solution by "inert" portions of a gaseous mixture prior to converting the ethylene oxide in solution. Furthermore, it would be desirable to provide a means for removing ethylene oxide from gaseous mixtures which does not rely upon the step of venting into the atmosphere or other such step where personnel are exposed directly to ethylene oxide.